Implement server-suggested update check backoff

chrome/browser/android/webapk/webapk_install_service.h

Index: chrome/browser/android/webapk/webapk_install_service.h
diff --git a/chrome/browser/android/webapk/webapk_install_service.h b/chrome/browser/android/webapk/webapk_install_service.h
index e22dc9aea4339ce035f0c2e10f3bda3a1b8aec69..0a4e9d9d967b28d2e751ecaac23824e949bf92d4 100644
--- a/chrome/browser/android/webapk/webapk_install_service.h
+++ b/chrome/browser/android/webapk/webapk_install_service.h
@@ -12,6 +12,7 @@
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
+#include "chrome/browser/android/webapk/webapk_installer.h"
 #include "components/keyed_service/core/keyed_service.h"
 #include "url/gurl.h"
 
@@ -26,11 +27,7 @@ class SkBitmap;
 // WebAPK on the server, download it, and install it.
 class WebApkInstallService : public KeyedService {
  public:
-  // Called when the creation/updating of a WebAPK is finished or failed.
-  // Parameters:
-  // - whether the process succeeds.
-  // - the package name of the WebAPK.
-  using FinishCallback = base::Callback<void(bool, const std::string&)>;
+  using FinishCallback = WebApkInstaller::FinishCallback;

[dominickn, 2017/03/06 02:28:36]

Minor nit: instead of having this defined in two places, it would be nice just
to have one definition, and then use that.

[Xi Han, 2017/03/06 22:14:21]

It is a little bit redundant, but I couldn't find a better place to put it:(
Introducing another independent FinishCallback class will add complexity to the
installer. Unless we can find an obvious way to clean it up, we may just keep it
as it is now.

 
   static WebApkInstallService* Get(content::BrowserContext* browser_context);
 
@@ -64,6 +61,7 @@ class WebApkInstallService : public KeyedService {
   void OnFinishedInstall(const GURL& web_manifest_url,
                          const FinishCallback& finish_callback,
                          bool success,
+                         bool relax_updates,
                          const std::string& webapk_package_name);
 
   content::BrowserContext* browser_context_;